Isolation And Identiifcation Of Long-lived Elderly Intestinal Pro Bio Tics And Research Of Longevity Mechanism

This paper conducted measures to the total number of bacteria and lactobacilli inthe intestine of long-lived people from Hotan, Xinjiang and general people by themethod of microorganism separation and molecular identification. During theseparation of lactobacillus, screened out the bacterial strains of which have ability ofcholesterol, acid-tolerance, bile-tolerance and protease-tolerance, and fundamentallystudied and discussed the inhibiting mechanism of motabolite.The result of the experiment of measuring and classifying the numbers ofmicroorganism showed that, the total numbers of the bacteria and lactobacillus in theintestine of long-lived old people were7.2×10~6cfu/g and4.9×10~4cfu/g, separately;However, these were8.0×10~6cfu/g and7.3×10~3cfu/g, separately, in the intestine ofgeneral people.27bacterial strains screened out from the intestine of long-lived people andgeneral people by using Selective culture medium flat coating method and themorphological structure of the cell and bacterial colony, gram stain andphysio-biochemical characteristics,16S rDNA gene sequencing was analyzed. Theresults of phylogenial analyze showed that27bacterial strains belong to enterococcusand Acidobacterium Heim, separately. In which,18bacterial strains belong toenterococcus durans,1bacterial strain belongs to enterococcus faecium,5bacterialstrains belong to Lactobacillus plantarum plant subspecies,2bacterial strains belongto Pentose Lactobacillus and1bacterial strain belongs to Class of Lactobacillus casei.The result of the experiment of antibacterial showed that27bacterial strains havethe ability of antibacterial, but the ability of antibacterial of bacterial strains separatedfrom dung of long-lived old people was stronger than the general people's. Theinhibition effects of enterococcus durans R02-23, Lactobacillus plantarum plantsubspecies R03-13and Pentose Lactobacillus S04to three indicators wascomparatively good, can be further study the antibacterial mechanism of Probiotics (lactic acid). We were conducted antibacterial test by using these metabolites oflactobacillus-organic acid (Lactic acid, butyric acid and acetic acid) andbacteriocins(stable to temperature and sensitive to Protease) as main substrate. Theresults showed the two kind of substances have significantly antibacterial effects atthe low pH condition, which is essential condition to antibacterial activity, theantibacterial substances can played a role when the pH lower than4.50in our study.Cholesterol Widespread in animals body, is the components of cell membraneand take part in the biosynthesis of some Steroid hormone and cholic acid, but it maycause the occurrence and development of atherosclerosis and coronary heart disease ifthe content of Cholesterol higher than normal level. Therefore, thecholesterol-lowering ability out of body of experimental bacterial strains was studied.27strains of lactic acid bacteria have the cholesterol-lowering ability, removal ratewas between22.32%-78.57%, the removal rates of13strains (from long-lived oldpeople) of which were higher than average value. The maximum and minimumremoval rates of probiotics were78.57%and40.41%, respectively. Screened10bacterial strains which have higher cholesterol-lowering ability and detected thetolerances to acid and protease. The results showed that, the tolerances of these threebacterial strains (enterococcus durans R02-23, Lactobacillus plantarum subsp.Plantarum R03-13Lactobacillus pentasus S04) to acid, bile salt and protease werehighest.the cholesterol-lowering mechanism of the three bacterial strains(enterococcusdurans R02-23, Lactobacillus plantarum subsp. Plantarum R03-13and Lactobacilluspentasus S04) were studied and the results showed that they have the role in reducingthe cholesterol content of fermentation liquid and have some absorption andassimilation ability. By detecting the tolerance of the experimental becteria strains tosome level of supersonic wave, the correlativity between absorption and assimilation ability of the strains have identified and the cholesterol-lowering mechanism ofProbiotics initially confirmed.All the results showed that, bacteriostatic ability, cholesterol-lowering ability andtolerance to severe environment in gastrointestinal tract of these lactic acid bacteriasuch as R02-23, R03-13, S04is higher than these general lactic acid bacteria(R07-28,R05-35).Therefore, there is strong relationship between longevity of long-lived oldpeople and enterococcus durans R02-23, Lactobacillus plantarum subsp. PlantarumR03-13and Lactobacillus pentasus S04, the Specific content about this need to furtherstudy.